The principle of Bluetooth headphones is that the underlying wireless signal module headset itself has no charging interface, and can only be charged through the charging bin. Put the headset into the charging bin, and with the help of the two connected metal contacts, the charging bin can automatically charge the headset, which can be filled within 2 hours.
Taking the green TWS Bluetooth headset as an example, the battery capacity of the headset is 60mAh, and the unpowered headset is put back in the box, which can be filled in 1.5 hours.
The Bluetooth headset has a small battery inside, which is used to save power.